(1) Field of the Invention
The present invention relates to the field of high power loudspeakers and in particular, to a loudspeaker system, a loudspeaker and a loudspeaker horn providing a predefined coverage pattern fed by an optimally shaped wave front created by an array of multiple drivers.
(2) Description of Related Art
In the field of generating and distributing acoustic energy and in particular where the acoustic energy is to be received and recognized by a large number of listeners who are distributed over a given area, many loudspeaker arrangements use multiple horns. Horns generally have an expanding cross-sectional area moving away from the acoustic source such that, in general terms, the horn is used to direct the acoustical energy along the axis of the horn.
Horns have very specific directional acoustical energy distribution characteristics. These characteristics are utilized in applications where the listeners are within a predetermined area relative to the arrangement of the horns. Such applications include but are not limited to open and closed sports arenas, for example.
One conventional directional loudspeaker is disclosed in U.S. Pat. No. 4,344,504 issued to Bruce Howze on Aug. 17, 1998. In this patent, a loudspeaker is disclosed to allegedly have a uniform horizontal sound dispersion characteristics in a design angle while having minimal vertical sound dispersion. It utilizes multiple sound energy sources which form an elongated line source of sound energy, and a wave guide having an elongated input portion coextensive with the elongated line source. The planar side walls of the wave guide minimize sound dispersion in a direction parallel to the line source while expanding the sound dispersion in a direction perpendicular to the axis of the line source, thereby differentiating the sound dispersion between vertical and horizontal planes.
In the Howze directional loudspeaker, the line source is formed in a single plane and the mouths of the horns are also in a single plane.
The Howze directional loudspeaker suffers from a number of drawbacks. For instance, vertical sound dispersion is not constant with frequency over the intended bandwidth. Additionally, vertical sound dispersion is preferred in some environments, thus making the Howze directional loudspeaker inappropriate.